Photoluminescence of Yb3+-doped CuInS2 crystals in magnetic fields

Single crystals of Yb3+-doped CuInS2 were isolated by an In-flux technique. The Yb3+ concentration is estimated to be 4.5x10(19) cm(-3) in terms of th e Curie-Weiss behavior of magnetic susceptibilities. The intra-4f-shell tra nsitions of Yb3+ were resolved at low temperatures by photoluminescence pea ks at 1.2-1.25 eV. The Yb-related peak intensities are weak in comparison w ith those arising from defect and impurity centers in the host. The magneti c field dependence of photoluminescence spectra shows interesting differenc es among the Yb-related peaks, with only part of them being Zeeman split. A n energy level scheme on the basis of a single type of Yb3+ center in a tet ragonal crystal field is proposed to explain the temperature- and magnetic- field dependence of the optical spectra. (C) 2001 American Institute of Phy sics.